Same with my Challenger. I'll wash and dry it. Get up the next morning and the rotors are all rusty.If I wash my Corvette when the rotors are cold and put in the garage the rotors look that way in the morning. The steel is for stopping on, no nickel or chrome, or other hardening anti-rust additions. First stop it is gone, you can practically wipe it off - it sits all winter with no issues. Look on new car lot - most vehicles have it.